Needleless access port valves are widely used in the medical industry for accessing an IV line and/or the internals of a patient or subject. Exemplary patents or publications that describe needleless access port valves are disclosed in Pub. Nos. 2002/0133124 A1 to Leinsing et al. Publication No. US 2007/0191786 A1 and U.S. Pat. No. 6,871,838, both to Raines et al. The contents of each of the foregoing references are expressly incorporated herein by reference as if set forth in full. Generally speaking, prior art valves utilize a valve housing in combination with a moveable internal plug or piston to control the flow of fluid through a valve. The plug or piston may be moved by a syringe or a medical implement to open the inlet of the valve for accessing the interior cavity of the valve. When a fluid is delivered through the valve, fluid flow typically flows around the outside of the plug or piston in the direction towards the outlet. Upon removal of the syringe or medical implement, the plug or piston returns to its original position, either un-aided or aided by a biasing means, such as a spring or a diaphragm.
In some prior art valves, when the syringe or medical implement pushes the plug or piston, the plug or piston is pierced by an internal piercing device, such as a spike. The spike typically incorporates one or more fluid channels for fluid flow flowing through the pierced piston and then through the fluid channels in the spike. In yet other prior art valves, a self-flushing or positive flush feature is incorporated to push residual fluids confined inside the interior cavity of the valve to flow out the outlet when the syringe or medical implement is removed.
Concerns with prior art valves include microbial colonization and sterilization. The former has to do with bacteria growth within the valve housing and the latter with the ability to clean the inlet of bacteria growth, such as wiping the inlet and/or the piston with a swab. Pub No. 2002/0133124 A1 to Leinsing et al., previously incorporated by reference, teaches the use of an antimicrobial agents, such as silver, silver oxide, or silver sulfadiazine, that “maybe included in the material forming the flex-tube piston or may be added to the outer surface of the piston as a coating” to minimize or eliminate bacteria growth. However, no information was provided on the effectiveness of the antimicrobial agents on bacterial growth when added as an admixture and cured within a piston. Nor was there information provided on how the antimicrobial agents kill the bacterium when the agents are cured or confined within the piston walls. Presumably, when cured within the piston, at most, only metals trapped along the outer surfaces of the piston are active agents.